The present invention relates to chewing gum products containing an antimicrobial agent for killing microbes, particularly oral bacteria, for reducing or preventing dental plaque and caries and gingivitis, and to methods for treating the same, and the like.
There is a need in the dental arts for an improved means of promoting dental health and hygiene, including a means for reducing plaque and dental caries, gingivitis, and especially for killing microbes which cause these dental problems, as a result of improper and inadequate tooth brushing. Plaque may be removed to some extent by effective brushing of the teeth. However, some areas of the teeth, which are less accessible and cannot be easily reached by a toothbrush, are particularly susceptible to plaque formation and consequently to calculus. Left unhindered, the plaque increases in size and more tenaciously adheres to the teeth. Although brushing with a toothbrush and dentifrice is a widely recognized technique for maintaining dental health, the average person brushes only once a day for approximately one minute. Therefore, a great need exists for finding additional methods for improving daily oral hygiene.
Dental caries, which cause the progressive decay of teeth, are manifested by localized demineralization, caused by acids produced from bacteria that ferment carbohydrate foods. The process may begin when bacteria in the mouth adhere to a tooth surface, thereby forming a dental plaque. The plaque is a product of microbial growth, primarily derived from food residues in the mouth. Mucoproteins and minerals present in saliva and dead cells in the mouth also contribute to plaque formation. There is substantial evidence that dental plaque is the predominant etiological factor responsible for both dental caries and periodontal disease, due to the generation of acids within the plaque structure. Thus, dental compositions having antimicrobial properties are beneficial for killing oral bacteria that contribute to the formation of dental plaque.
A thin layer of dental enamel consisting mainly of calcium, phosphate, and other ions in a hydroxyapatite-like structure forms a protective coating over the tooth. When bacteria in a dental plaque metabolize the fermentable carbohydrates consumed by an individual the process of tooth decay, i.e., dental caries, begins. During this process, lactic acid and other organic acids, toxins and enzymes are secreted as by-products, having a deleterious effect on neighboring oral tissues. These secretions reduce the pH surrounding the tooth, causing the protective coating to dissolve when the pH drops below a critical level (approximately pH 5.5 to 5.7). Dental enamel comprising 2-5% carbonate is particularly susceptible to acid dissolution. Generally, dissolution of the enamel begins below the tooth""s porous surface. With repeated acid attacks, caused by further bacterial metabolism of fermentable carbohydrates, sub-surface lesions expand. If the lesions expand to the point that the enamel surface breaks, a cavity is formed and the process is no longer reversible.
Remineralization of a tooth requires the pH near the tooth to remain above the critical level. The remineralization process involves, in part, the flow of saliva over the tooth, which raises the pH of the tooth""s environment. Also, calcium and phosphate ions in the saliva precipitate to replace hydroxyapatite that has been dissolved by the organic acids secreted by bacteria. Therefore, an oral antimicrobial composition that increases the amount of saliva in the mouth for extended periods after eating would be beneficial for the remineralization process.
Chewing gum is an excellent adjunct for cleaning teeth since people generally chew gum for much longer periods of time than for brushing. It is especially advantageous when brushing is inconvenient or not possible. Chewing gums provide an excellent delivery system for an antimicrobial composition because of the prolonged contact with the oral cavity during use, and due to the fact that a gum base can provide for the sustained release of the active components. Furthermore, mastication causes the release of saliva into the mouth, and assists in increasing pH levels, which become lowered as a result of bacterial metabolism of fermentable carbohydrates. Consequently, the increase in pH reduces the likelihood that dental caries will form, and therefore certain chewing gums promote dental health and hygeine. However, a chewing gum product that also has antimicrobial properties greatly increases the gum""s effectiveness as an agent for reducing plaque formation and dental caries because it acts to kill and reduce oral microbes that are at the root of many dental health and hygiene problems. Moreover, a chewing gum having inorganic antibiotic ingredients which are non-toxic and do not induce resistance in bacteria would be highly advantageous.
Organic antimicrobial agents in oral compositions found in chewing gum, that exhibit microbial-, plaque- and calculus-inhibiting properties are known in the art. For example, U.S. Pat. No. 4,022,880 issued to Vinson et al. describes compounds providing zinc ions admixed with an organic antibacterial agent effective for retarding the growth of plaque bacteria. U.S. Pat. Nos. 5,037,637, 5,043,154, 5,080,887, 5,292,526, and 5,686,064 issued to Gaffar et al. describe the use of Triclosan and an antibacterial-enhancing agent which optimizes or enhances delivery and retention of the antibacterial agent on oral surfaces. U.S. Pat. No. 5,028,414 issued to Sampathkumar et al. describes use of substituted or unsubstituted 1,12-dodecanedioic peroxy acids as antimicrobial agents in chewing gums. U.S. Pat. No. 4,559,223 issued to Fox et al. discloses a method of inhibiting microbial mouth infections and dental caries, plaque formation, gingival destruction and tooth loss by contacting teeth with a composition comprising silver and/or zinc sulfadiazine.
Unfortunately, however, bacteria may become resistant to organic antimicrobial agents. There is therefore a need for an antibiotic chewing gum formulation that avoids use of organic compounds that can induce development of resistant bacterial strains. Thus, an inorganic antimicrobial composition in chewing gum would prove beneficial. There is also a need for a chewing gum formulation that leaves an effective antibiotic residue that continues to kill plaque-forming bacteria for a substantial period after using the chewing gum.
The present invention relates to chewing gum products containing microbicidally effective amounts of a composition comprising an inorganic ceramic carrier retaining antimicrobial metal ions. In a preferred embodiment, the inorganic ceramic carrier is a zeolite which retains antimicrobial silver ions.
Thus, the present invention provides novel chewing gum products having antimicrobial properties which overcome many problems in the dental health and hygiene arts. The chewing gum products of the invention are effective in killing and reducing oral bacteria and microbes and, consequently, in protecting against dental plaque and caries formation, gingivitis, and the like. Methods for treating the same are also disclosed.
Accordingly, this invention provides novel chewing gum products having antimicrobial properties derived from an inorganic antimicrobial agent, and that serve as a convenient adjunct for improved dental health. The antimicrobial properties of the invention are derived from antimicrobial metal ions that are ion-exchanged with an inorganic ceramic carrier. As an antimicrobial agent, the metal component in the chewing gum is released into the mouth during mastication where it can contact oral microbes involved in plaque and dental caries formation. As the chewing gum contacts the oral cavity and surfaces of the teeth, antimicrobial metal ions retained in the gum can kill microbes thereon. The killing of oral microbes consequently reduces or prevents plaque or dental caries formation.
Thus, the invention provides an antimicrobial chewing gum product that is effective in killing oral microbes, including bacteria, and consequently reduces or prevents the formation of plaque and dental caries, and associated periodontal disease.
It is an advantage of this invention that an antimicrobial oral composition for use in chewing gum is provided which is also effective for reducing the occurrence of gingivitis.
It is also an advantage of the invention that the antimicrobial metal ions employed are effective in combination with known antiplaque and anticalculus oral compositions.
It is a further advantage of the invention that the antimicrobial agent is inorganic, well-tolerated in humans, and does not induce resistance in bacteria.
It is still another advantage of the invention that the antimicrobial particles remain in gum spaces, providing long-lasting action. Moreover, particles retained on the teeth and gums following chewing can continue to release the antimicrobial metal component over an extended period.